Product dispensers for compelling a flowable product from a deformable container are known in the art. Some of them are described in U.S. Pat. No. 4,125,206 issued to Wilson on a toothpaste dispenser; U.S. Pat. No. 4,508,242 issued to Wolfe on a toothpaste extractor and U.S. Pat. No. 6,318,596 issued to Wiesner on a product dispenser.
Certain prior art product dispensers may include a screw or worm gear retained within a frame having a squeezing member received upon the screw to travel from a first end of the screw to a second end of the screw to compel a flowable product from a container. Once the squeezing member has reached the end of its travel at the second end of the screw, a user must actuate the squeezing member and, therefore, the screw in a reverse direction so that the squeezing member travels along the screw back towards the first end.
Some of these prior art product dispensers require the squeezing member to travel along the length of the screw first to dispense product from a container and then reverse its direction along the screw without any work performed other than to return the squeezing member back to its origin. This requires unproductive time on the part of the user to reconfigure the dispenser for subsequent use. Further, this type of mechanism is inefficient and causes undue fatigue upon a user's fingers with manually actuated product dispensers and undue stress upon mechanical and electrical parts in an automatically actuated product dispenser, leading to accelerated mechanical and/or electrical failure of prior art product dispensers. In addition, these prior art product dispensers are generally complex in order to accommodate both forward and reverse travel of the squeezing member retained within the frame. These product dispensers have many moving parts and are not economical to manufacture or repair.
Other prior art products that include a squeezing member mounted on a screw may not require reversal in the direction of travel of the squeezing member to return it to its origin. These products, however, may include an actuating member in the form of a rotatable knob that controls travel of the squeezing member. A problem with this type of configuration, however, may lie in the relatively large magnitude of the force required to rotate the knob and cause travel of the squeezing member against the surface of the container holding the flowable product being dispensed. This problem is accentuated when the user of the product is a small child or a person with limited hand strength.
A product dispenser that does not require reversal of travel of a squeezing member while requiring a relatively low magnitude of force to be applied to an actuating member controlling travel of the squeezing member is therefore desirable.